Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
  • B60C11/1204—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe
  • B60C11/1218—Three-dimensional shape with regard to depth and extending direction
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
  • B60C11/1236—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special arrangements in the tread pattern
  • B60C11/124—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special arrangements in the tread pattern inclined with regard to a plane normal to the tread surface
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
  • B60C11/1272—Width of the sipe
  • B60C11/1281—Width of the sipe different within the same sipe, i.e. enlarged width portion at sipe bottom or along its length
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
  • B60C11/1204—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe
  • B60C2011/1209—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe straight at the tread surface
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
  • B60C11/1204—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe
  • B60C2011/1213—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe sinusoidal or zigzag at the tread surface
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
  • B60C11/1236—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special arrangements in the tread pattern
  • B60C2011/1254—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special arrangements in the tread pattern with closed sipe, i.e. not extending to a groove
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S152/00—Resilient tires and wheels
  • Y10S152/03—Slits in threads

Definitions

• a tread for a tire of a heavy goods vehicle comprises grooves of general circumferential or longitudinal orientation (by general orientation is meant here that these grooves extend in the circumferential direction but that they can be rectilinear or zigzag). It is customary to differentiate tread patterns from the tread pattern to the axle on which the tire is mounted.
• the tire tire tread is furthermore provided with a plurality of grooves of generally transverse orientation (by transverse general orientation, it is meant here that the average direction of these grooves may be parallel with the direction of the axis of rotation of the tire or make an angle different from zero with said axis).
• the circumferentially and transversely oriented grooves of such a strip delimit at least in the middle portion of the tread at least one so-called "intermediate row" formed of a succession of relief elements in the form blocks of rubber material, these blocks having average heights equal to the depth of the branches delimiting them.
• Each block comprises a contact face intended to come into contact with the roadway while driving and side faces intersecting said contact face to form ridges.
• the first edge coming into contact with the running roadway corresponds to the so-called “leading edge” edge and is formed by the intersection of the contact face with a lateral face called “leading face” of the block.
• the last edge leaving the contact being called “trailing edge” formed by the intersection of the contact face and a side face called “trailing face”.
• each block can be provided with at least one incision (that is to say a cutout whose faces vis-à-vis are at an average distance l)
• an incision that is to say a cutout whose faces vis-à-vis are at an average distance l
• two additional ridges are created which are useful for cutting the film of water present on the roadway in rainy weather.
• the object of the invention is to propose a tread intended to form the portion radially outwardly of a tire intended to be mounted on a driving axle of a heavy goods vehicle and which makes it possible to achieve a satisfactory performance in adhesion while having the most regular wear possible blocks of the intermediate rows (that is to say a uniformly distributed wear on the contact face of each block of the intermediate rows).
• a tire tread intended to equip a driving axle of a heavy goods vehicle (truck, bus), this tread comprising at least two circumferentially oriented grooves and a plurality of branches of general transverse orientation delimiting at least one intermediate row of blocks and rows edge delimiting axially and transversely this tread.
• Each block of the intermediate rows has side faces, a contact face intersecting the lateral faces to form ridges, the edge provided to enter the first contact with the rolling road corresponding to the leading edge formed by the intersection of the contact face with a lateral face called the leading face of the block, the edge coming out last of the contact being called the trailing edge, the latter being formed by the intersection of the contact face and a side face said trailing face.
• the leading face is, with a perpendicular to the contact face and passing through the leading edge, an average angle OcA which is greater than zero degrees
• the trailing face making, with a perpendicular to the contact face and passing through the trailing edge, an average angle OCF which is greater than zero degrees
• the angle OcA of the leading face being greater than the angle OCF of the the trailing face
• the leading and trailing faces of the same block being oriented so as to deviate from one another by going from the running surface to the inside of the strip.
• Each block of at least one intermediate row comprises an incision extending in the thickness of the block over at least one depth equal to the depth of the transverse grooves delimiting said block and from one lateral face to another lateral face of the block, this incision being delimited by vis-à-vis faces provided with locking means relative movements of one of said faces relative to the other face in at least one direction, this incision cutting the contact face of the block, in the new state, in two surface parts of substantially equal areas.
• substantially equal areas it should be understood that these areas are equal to or differ by no more than 1%.
• the angle of the incision ⁇ is greater than zero degrees and smaller than 30 degrees.
• the angle of the attack face OcA is less than 45 degrees.
• the difference between the volumes of material between the leading face and the incision and between the trailing face and the same incision is at least equal to 1% of the largest of said volumes.
• the difference between the volumes of material between the leading face and the incision and between the trailing face and the same incision is at most equal to 15% of the largest of said volumes.
• the tread according to the invention is provided on a plurality of blocks and on at least one of the volume portions of the blocks located between the incision and the leading face or between the incision and the trailing face, with at least one blind elongate cavity (incision or well or hole), that is to say, opening only on the contact face of the blocks.
• these blind elongated cavities have depths equal to or close to the depth of the inclined incision and are themselves inclined by an average angle different from zero degrees relative to a perpendicular to the tread surface, this angle being likewise meaning that the angle of the face attacks the blocks, and at most equal to the angle that makes said face attack.
• the invention also relates to a directional tire, that is to say that must be mounted on a heavy vehicle in a precise way to turn in a given direction when driving forward of the vehicle.
• This tire is provided with a tread as described and further comprises means (sign or marking) apparent indicating the preferred direction of rotation of the tire.
• This sign or marking may take the form of at least one arrow molded on the sidewall of the tire or on the lateral part of the tread itself.
• Figure 1 shows a view of the running surface of a portion of a tread according to the invention
• Figure 2 shows a sectional view of a portion of a row of blocks of the tread as shown in Figure 1
• Figure 3 shows another variant of the tread according to the invention
• Figure 4 shows a partial view of the variant shown in Figure 3;
• Figure 5 shows a tread variant further provided with blind elongate cavities
• Figure 6 shows a section of the tread shown in FIG.
• Figure 1 shows a view of the tread surface of a tread 1 according to the invention.
• This figure 1 indicates the direction of rotation of the tire provided with such a band that it is necessary to respect in order to achieve the expected results; this direction of rotation is indicated in the figure by an arrow R.
• This tread is provided with four rectilinear grooves 2 oriented circumferentially and sharing this band in two edge portions 51 located axially outside the band and an intermediate portion 4.
• the intermediate portion 4 comprises three rows of blocks 6 delimited by both the circumferential grooves and transverse branches 3 parallel to the axial direction (that is to say the direction of the axis of rotation marked by XX ' on the face).
• Each block 6 comprises side faces and a contact face 60, the latter being substantially parallel to the plane of FIG. 1.
• the set of faces of contact of the relief elements of the strip forms the tread surface 10 of the tread 1 intended to come into contact with the roadway during driving.
• each block 6 is delimited by four edges. These edges are the intersections of the contact face 60 with each of the lateral faces.
• the edge of a block entering first the contact during the rolling (according to the direction of rotation given by the arrow R) is said leading edge A while the edge of the same block leaving the last contact is said trailing edge F.
• lateral face intersecting the contact face 60 along the leading edge A corresponds to the leading face 61 whose intersection with a plane perpendicular to the axis of rotation is shown in FIG.
• lateral face intersecting the contact face 60 along the trailing edge F corresponds to the trailing face 62 whose intersection with a plane perpendicular to the axis of rotation is shown in FIG.
• the leading face 61 intersects the plane of Figure 2 along a line TA; this line TA makes an angle OcA with a perpendicular Pl to the contact face 60 passing through the point of intersection of the leading edge A with the sectional plane of FIG. 2.
• the trailing face 62 intersects the plane of Figure 2 along a line TF; this line TF makes an angle FF with a perpendicular P2 to the contact face 60 passing through the point of intersection of the trailing edge F with the sectional plane of FIG. 2.
• angles OcA and ⁇ F are such that the The average width of a transverse branch decreases with depth (the leading and trailing faces tend to converge towards a perpendicular PO passing through the middle of the groove on the running surface (the leading face converging faster than the trailing face).
• the angle OcA is in this case equal to 12 degrees.
• the angle ⁇ F is in this case 5 degrees.
• the transverse grooves have an average depth H.
• Each block of the rows of blocks of the intermediate portion 4 of the tread is provided with a single incision 7 intersecting the contact face 60 in a mean trace 70 visible in Figure 1; this average trace 70 is, in this case, rectilinear on the strip in the new state and is parallel to the axis XX '. This average trace 70 cuts the contact face so as to divide this face into two parts of equal areas.
• the incision 7 is inclined in the depth of the block by an average angle ⁇ , measured relative to the perpendicular to the running surface, in the same direction as the angle OcA of the leading face .
• ⁇ measured relative to the perpendicular to the running surface
• the inclination of the incision 7 (in the present example equal to 10 degrees) and that of the leading face (in the present example equal to 12 degrees) are determined so as to delimit between it a volume of VA material which is smaller than the VF volume that the same incision delimits with the trailing face of the same block.
• the difference (VF-VA) between these two volumes is here equal to 6.5% of the largest volume.
• these volumes VF, VA are measured between the contact face (limited by the curved surface S tangent to the contact face 60 of the block and a curved surface S 'substantially parallel to the surface S and passing by the bottom of the incision 7.
• the strip comprises an intermediate portion formed of four rows of blocks of non-rectangular shape (six edges of different orientation delimit the contact face of each block). These blocks are delimited by non-rectilinear circumferential grooves (here zigzag) and oblique transverse grooves that is to say making an angle ⁇ different from zero degrees with the transverse direction (equal in this case to 11 degrees). In other variants not shown here, this angle ⁇ may be chosen different from the angles of the leading and trailing edges.
• FIG. 3 shows a view of the tread surface of a tread 1 having an imposed rolling direction and which can be indicated on the tread by a visible means (this direction is indicated in FIG. an arrow R).
• This tread is provided with five rectilinear grooves 2 oriented circumferentially and sharing this band in two edge portions 51, 52 located axially outside the band and an intermediate portion 4.
• the intermediate portion 4 comprises four rows blocks 6 delimited by both the circumferential grooves and transverse branches 3 forming an angle ⁇ with the axial direction (represented by the direction YY '), this angle ⁇ being here equal to 11 degrees.
• Each block 6 comprises side faces and a contact face 60, the latter being visible only in this figure 1.
• the set of contact faces of the relief elements of the strip forms the tread surface 10 of the tread 1 intended to come into contact with the roadway during driving.
• the contact face 60 of each block 6 of all the rows of the tread except for the rows of the edge portions is divided into two parts of equal areas by an incision opening on this face.
• the average trace 70 of the incision on the contact face follows an average profile which is substantially parallel to the leading and trailing edges; this trace 70 is therefore an angle of 11 degrees equal to the angle ⁇ with the axial direction YY '.
• the direction of the trace of the incision on the contact face of a block is parallel to the bisector of the angle formed by the mean directions of the transverse branches delimiting this block.
• Each block 6 of the rows of the intermediate portion 4 is provided with a single incision 7 which is inclined in the depth of a mean angle ⁇ with respect to a plane perpendicular to the contact face passing through the average trace 70 incision on the contact face 60; this incision 7 is oriented so that the points of the innermost incision of the tread tend to move further and further away from the points of the trailing face so as to delimit with the leading face 61 a block volume which is smaller than the volume that the same incision 7 delimits with the trailing face 62.
• the incision 7 is generally flat and cuts the lateral faces of each block according to a trace T (the trace of the incision corresponds to the intersection of the plane means of the incision with the contact face of the block) making a mean angle ⁇ with plane P3 perpendicular to the contact face and following the intersection of the incision with the contact face. This angle is in this case 6 degrees. This same incision is delimited by material walls vis-à-vis distant about 0.4 mm.
• the walls defining the incision 7 are provided with locking means 71 interacting with each other to reduce or cancel any relative displacement of one wall relative to the other during the passage in contact with the roadway while taxiing; relative displacement here means that the locking means are effective to achieve a blocking of any displacement of one wall relative to the other in two different directions, namely in the direction of the thickness of the strip and in a direction perpendicular to the direction according to the thickness, this perpendicular direction being contained in the mean plane of the incision.
• the incision centered on the contact face of a block is such that in combination with the inclination of the leading face it delimits a volume VA which is smaller than the volume VF delimited by the same incision and the flight face.
• these volumes are measured between the contact face (limited by the curved surface S) and a curved surface S 'parallel to the surface S and passing through the bottom of the incision.
• the incision 7 is further extended over its entire length by a portion 72 which is wider than the average width of the incision.
• this enlarged portion 72 opens at its ends on the lateral faces of the block 6 and is of substantially oblong cross-section of average width equal to 4 mm and of average length equal to 8 mm (this part does not intervene in the evaluation of VA and VF volumes).
• the volume VA here is equal to 98% of the volume VF.
• the blocks of the edge portions 51, 52 of the tread are completely devoid of incisions.
• These blind elongate cavities 80 only open on the contact face of the blocks and not on the lateral faces of the blocks and have depths equal to or close to the depth of the inclined incision 7 and are themselves inclined by an average angle ⁇ different from zero degrees with respect to a perpendicular to the running surface, this angle ⁇ being in the same sense as the angle OCA of the attack face of the blocks, and in this case equal to the angle OCA that said attacking face makes .
• These additional cavities generate additional ridges on the contact face without significantly affecting the compression and shear stiffness of the blocks. Moreover their inclination chosen to be in the same sense as that of the leading face and that of the incision is also favorable in wear.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Tires In General (AREA)

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Applications Claiming Priority (2)

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Citations (7)

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• 2008
  • 2008-03-20 FR FR0851796A patent/FR2928866B1/fr not_active Expired - Fee Related
• 2009
  • 2009-03-20 JP JP2011500237A patent/JP5285762B2/ja not_active Expired - Fee Related
  • 2009-03-20 CN CN200980109558.0A patent/CN101977783B/zh active Active
  • 2009-03-20 WO PCT/EP2009/053322 patent/WO2009115606A1/fr active Application Filing
  • 2009-03-20 US US12/933,624 patent/US8936055B2/en active Active
  • 2009-03-20 EP EP09722560.1A patent/EP2262652B1/fr active Active
  • 2009-03-20 EA EA201071106A patent/EA016694B1/ru not_active IP Right Cessation
  • 2009-03-20 BR BRPI0909266-8A patent/BRPI0909266A2/pt not_active Application Discontinuation

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